I've found that APM is an excellent tool for giving companies pro-active monitoring and alerting capability.
If used correctly it gives you the ability to get the jump on system / application issues based on performance thresholds. That 5-10 minute gap between identifying something is going wrong to something is wrong is critical for reducing impact to customers being either internal or external.
It really takes a lot of in depth understanding of your applications to get the best out of this tool, something that many organisations don't have. On that note, this tool can give them that ability.
It takes a lot to configure and what you get out of it is dependent on what you put in. Something that in-depth planning is definitely required.
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